Automatic brake for elastic-fluid turbines.



0. JUNGGRBN.

AUTOMATIC BRAKE POR BLASTIQ FLUID TURBINES. APPLICATION FILED AUG, 7, 1903.

910,388. Patented Jan. 19, 1909.

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0. JUNGGRN. AUTOMATIC BRAKE .FOR BLASTIG FLUID TURBINBS. APPLICATION FILED AUG.7,`1903.

910,388. l Patented Jan. 19, 1909.

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Witnesses:

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0. JUNGGREN.

AUTOMATIC BRAKE FOR ELASTIG FLUID TURBINES.

APPLIGATION FILED AUG. 7, 1903.

910,388. Patented Jan. 19, 19o9.

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OSCAR JUNGGREN, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

AUTOMATIC BRAKE FOR ELAS-TIG-FLUID TURBINES.

Specification of Letters Patent.

Patented' Jan. 19, 190,9.

Application led August 7, 1903. Serial No. 168,592.

To all whom 'it may concern.

Be it known that I, OSCAR JUNGGREN, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Automatic Brakes for Elastic-Fluid Turbines, of which .the following is a specification.

This invention relates to elastic Huid turbines and especially to those in which the rotating shaft is upright and is supported upon .a step-bearing in which the bearing surfaces vare separated 'b a thin lm of oil or other lubricant force in under heavy pressure. As the weight on these step-bearings is considerable, amounting sometimes to sixty or seventy tons, it is absolutely necessary that the ressure of the oil supply system should not fa l below a certain predetermined minimum, while the machine is running. If, forany reason, such as a break-down of the .lubricant pump or a choking of the lubricant pipe, the pressure should fall and allow the bearing surfaces to come in contact, they would quickly grind themselves to pieces even if steam were shut off promptly, since the momentum of the rotating parts is suflicient :to keep them moving long enough to ruin the bearing after the steam is shut ofi.

The object of my invention, therefore, is to romptly check the rotation of the shaft and its attached arts in case the lubricant-pressure falls be ow a predetermined safe miniing, theconstruction `and arrangement being such that upon failure of this 'pressure the brake dll vbe immediately app ied and the -shaft will be quickly stopped.

In .the accompanying drawings Figure 1 is a vertical section of the lower portion of a -steam turbine showing my invention applied thereto; Fig. 2 is 'a top plan .view of the same partly in section; Fig. 3 is a side elcvationshowing a modificatlon; and Fig. 4 is .atop plan viewfof the same.

Referring to Figs. 1 and 2, the shaft 11 is suplported 1n a step bearing contained in a she creasing 2 and comprlslng 'a rotating bearing block 3 secured .to the end of the shaft, and a stationary bearing block 4 .located ina seat 1n the plate 5 which is secured to the casing 46 .of the machine. Formed partly in the lower .block and partly 1n the upper block, which is attached to .the maln shaft, is a chamber which receives fluid lubricant under pressure, referably oil. The pressure in this .chamliier varies with the lweight ofthe moving parts. In certain instances it is as high as fifteen hundred pounds per square inch, ,and this pressure is sufficient to sup ort the weight of the rotating shaft and t e parts attached thereto, a .thin film of lubricant being constantly maintained between the adjacent surfaces of the bearing blocks when the machine is in .operation. The lubricant is :conveyed .to the chamber by a pi e 7 wxhich leads from a suitable source o sup ly, such .as a forcepump, 7. The detail; of construction vof this bearing are fully set forth in a .pending application Vof 1William L. R. Emmet and myself, filed June 25, 1903, Serial No. 163,660 which issued as Patent No. 874,945? on Dec. 31, 1907.

Secured to :the shaft 1, and rotating therewith, is a .collar 8. A flexible brake lband I9 encircles .the collar =8 and is .attached ateach end Vto a lever 10 pivoted at :a point .1l ebetween the ends of the bra-ke band, on va bracket 12, secured .to the side ofthe shell 2. One end oftheflever is iivotally connectedto arod 13 which is rigidl able abutment, such asa plunger 14 movable in a fixed .cylinder 15 which is 'suitably mounted on the frame of :the machine. The plunger has a long bearing in fthe ,cylinder and is provided with packing rings to makea tight joint. By means of a short 'branch pipe 16 leading from the yoil pi e 7 -the oil Apressure .is .conveyed to the bac endof .the

,cylinder 15. ln'order'to prevent any'poss'ible leakage .of the .oil past ,the plunger, gthe forward endofzthe `plunger is conical l1n order to seat itselflike a-valve upon the conical internal shoulder 17 near :the front endlof the cylinder.

By means. ofthe oil pressureon the abutment, the brake is maintainedfin ain-inoperative position, as shown in Fig. 2. Means are provided for applying the .brake incase the pressure falls below a .safe minimum; .con-

sisting preferably of asprmgconnectedwith the lever 10 and put -undeiwtension when .the plunger is moved to itsseat .bythe oil pressure. The spring isconveniently locatedebetweenthe abutment :14 on .the vrod landa stationary support, such as the front end of the cylinder, in which case a helical spring 18 may bc used.

'llie operation of the device is as follows: ll'hen the oil pressure falls below a predetermined minimum so that it is no longer able to maintain the bearing blocks 3 and 4 separated and also the plunger 14 iii the position shown in Figs. 1 and 2, the tension of the spring will force the plunger backward and move the lever 10 in such a way as to apply the brake band 9 to the collar 8 and thus quickly check the rotation of the shaft and stop it despite the fact that power or the supply of steam to the turbine is not shut oil'. In order to obtain the best results it is necessary that the branch pipe 16 should lead from the pipe 7 at a point as near as possible to the step bearing. This insures a similarity of pressure in the bearing and c linder and also minimizes the danger of fai ure to operate by a choking of the pipe 7 between the step bearing and the point at which the branch pipe leaves it.

In the modifications shown in Figs. 3 and 4, the movable brake element consists of the ring 19 loosely supported on the upper end of the sleeve 2() which encircles the shaft and is firmly bolted to the upper end of the shell 2.

The ring is prevented from rotating with the shaft by means of lugs 21 which project upward from the sleeve 20 into openings in said ring. Between the iing and the lower flanged end of the sleeve is arranged a pair of toggles 22, preferably one on each side of the shaft. ilhen the toggles are straightened out the ring will be lifted and forced into contact with the collar 8 on the shaft and thereby operate as a friction biake to stop the rotation of the shaft. The toggles are connected by rods 23 with a cross head 24 and the cross head in turn is attached to the end of the plunger rod 13. By means of nuts 25 the parts can be properly adjusted to give an equal upward pressure on both sides of the rin ligt will be seen that my invention provides a simple and eilicient means for promptly checking the rotation of the shaft of an elastic fluid turbine Whenever the pressure of the lubriant supplied to the step bearing falls beloW a predetermined safe minimum.

In the modifications shown in Figs. 3 and 4, the brake not only serves to stop the shaft but tends to lift it slightly so as to keep the bearing blocks separated and prevent them from exerting a destructive effect upon each other. Moreover, so long as the brake remains applied, the engine can not be started, so that there is no danger of accidentally injuring the step-bearing by starting the engine Without proper oil pressure on the bearing.

In accordance with the patent statutes, I have described the rinciple of operation of my invention toget er with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

Vrhat I claimas new and desire to secure by Letters Patent of the United States, is-

1. The combination with a rotating shaft, of a bearing therefor comprising superposed blocks normally separated by a continuously flowing film of fluid under pressure, a device supplying fluid to maintain said film, an automatic brake for said shaft, and means responsive to changes in the fluid ressure sup lied to said bearing for actuating said bra e.-

2. Tliecombination with a rotating shaft, of a bearing therefor comprising superposed relatively rotatable blocks normally separated by a continuously flowing film of fluid under pressure, a device supplying fluid to maintain said film, a brake mechanism for the shaft, which is o erated automatically to check the rotation o said shaft when the supply of lubricant to the bearing decreases beyond a predetermined limit, and means responsive to the pressure of the fluid supplied to the bearing for applying and releasing said brake.

3. A shaft, bearing blocks for supporting the shaft, and a device which under normal conditions causes a film of lubricant under pressure to flow between said blocks, in comination with a brake which when applied tends to move the shaft and relieve the pressure on the bearing blocks due to the weight of said shaft and its attached parts,and means responsive to the pressure of the lubricant supply which app ies the brake when said pressure falls below normal.

4. The combination with a shaft and a bearing comprising a pair of relatively rotatable blocks, of means for normally main taining a constantly flowing i'ilm of lubricant between the blocks, a device for preventing said shaft from being rotated when the supply of lubricant is below a predetermined imit, and means responsive to variations in said supply of lubricant for actuating said device.

5. The combination with a shaft and its bearing, of means for supplying said bearing with fluid under pressure, a brake adjacent the bearing for checking the rotation of the shaft which when a plied tends to relieve said bearing of weig it of the shaft and its attached parts, and means for automatically and ositively actuating the brake when the supp y of iluid to the bearing falls below a predetermined limit.

6. The combination with a shaft and a bearing located at one end of the shaft and comprising blocks normally separated by a continuously flowing film of lubricant, of means for supplying said bearing with uidlubricant under pressure, a brake for arresting the rotation of the shaft, a spring for applying said brake, and an abutment moved y said pressure and opposing the energy of said spring.

7. The combination With a shaft having a bearing comprising opposed blocks, one of which has an opening to receive iuid, of means for supplying said bearing With fluid- 10 lubricant under pressure through said opening, a brake to arrest rotation of the shaft, a s ring for applying said brake, a cylinder, a unger in said cylinder connected with said rake, and a connection between said cylin- 5 der and the fluid lubricant sup ly.

8. The combination with a s aft having a bearing, of a pipe; for supplying said bearing with uid lubricant under ressure, a brake,

l OSCAR JUNGGREN. i

Witnesses BENJAMIN BHULL, HELEN ORFORD. 

